LIFE-HISTORY OF TORTRIX PRONUBANA. 51 



food-plant and the glass, and was thus under observation during 

 the first two or three weeks of its existence ; it fed upon the 

 fleshy part of the back of the leaf, but did not penetrate to 

 the front. The first moult took place on August 7th, when the 

 larva became a yellowish-green colour, the head assumed a 

 browner appearance, and the length had increased to 4^ mm. 

 By the 18th it had moulted again, measured 7 mm. in length, 

 and had become pale green in colour, the head still maintaining 

 the brownish appearance. 



Soon after this it became necessary to change the food, and 

 as the larvse all spun themselves in between leaves it was im- 

 possible to keep so close a watch upon them as formerly, but on 

 turning them out some two to three weeks later it was found that 

 they varied very considerably both in size and colour, some two 

 or three being in their last skins, while a larger number appeared 

 to be about half-grown, and the chief difference noticeable in them 

 since their second moult was that the colour of their bodies had 

 become a more decided green. 



The full-fed larva measures 15 mm. to 20 mm. in length. 

 The head is smaller than the second segment, glabrous, horn- 

 colour, and has two or more dark brown or black patches at its 

 base, and sundry dark brown or black markings about the mouth- 

 parts ; the intensity and number of these dark markings varying 

 in individuals. The thoracic plate is glabrous green, with four 

 (more or less) blackish -brown, irregularly angulated patches 

 along its posterior margin. The body tapers towards each end, 

 is olive -green on the back to the lateral skin-fold, which, as well 

 as the ventral surface, is paler ; the anal segment also is paler. 

 On the back of each segment are four slightly raised paler tubercles 

 and below them on each side another, each emitting a stiff 

 whitish bristle, and on the skin-fold is yet another, from which 

 two bristles spring, the whole giving the larva a somewhat hairy 

 appearance. 



The first moth emerged on September 18th, and was followed 

 by others at somewhat lengthy intervals until December 13th, 

 this last having been in pupa for some five or sis weeks, during 

 the latter part of which it was kept in a cool greenhouse to pro- 

 tect it from any actual frost. The remainder of the larvae are 

 hybernating (?), approximately full-fed, and as those from the 

 September-October moths pass the winter quite small, there 

 appears to be good reason for supposing that the imagines are 

 on the wing throughout the summer and autumn months. 



Explanation of Plate II. — 1. Tortrix pronuhana, ^. 2. Ditto, $• 

 3. Larva, dorsal view, slightly enlarged. 4. Larva, lateral view, slightly 

 enlarged. 5. Segment of larva, enlarged, dorsal view. 6. Enlarged sectional 

 view of larva. 7. Mass of ova x 100. 



Lewisham : February, 1908. 



E 2 



